Circuit breaker with liquid or gas blowout



Nov. 27, 1934. A. CLERC CIRCUIT BREAKER WITH LIQUID OR GAS BLOWOUT Filed Jan. 11, 1934 Patented Nov. 27, 1934 CIRCUIT BREAKER WITH LIQUID OR GAS BLOWOUT Andr Clerc, Villeurbanne, France, assignor to Societe Ateliers De Constructions Electriques de Belle, Paris, France Application January 11, 1934, Serial No. 706,271 In Germany January 23, 1933 8 Claims.

The object of my comnding U. S. patent application No. 658,085, filed February 23rd, 1933, refers to an electric circuit-breaker in which the arc is lengthened out and extinguished by a blast of liquid or gaseous extinguishing fluid, and in which in open position one of the contacts or an electrode connected to said contact is disposed in the central zone of the extinguishing blast. The principal characteristic of this circuit-breaker is an extremity electrode connected to the second contact, said extremity electrode being also disposed in the centre of the extinguishing blast. v

In certain embodiments described in said copending patent application, the two electrodes are situated, for a certain portion of their length, along the axis of the extinguishing blast in such manner that the arc flowing between their opposed extremities-disposes itself along a straight line between said extremities in the manner of a jet of water issuing from a nozzle. In this manner, the choice of the distance between the two central electrodes permits a limitation of the length of the arc to a predetermined value.

However, it has been observed that the conductors connecting the extremity electrode to its corresponding contact are capable of exerting on the arc electrodynamic forces which tend to deflect said are in the form of a how. This lengthening of the arc increases on the one hand the energy dissipated in the apparatus and on the other hand the pressure existing in the interior of the chimney, thus creating unfavourable conditions for the extinction of the arc.

The present invention remedies this disadvantage. It consists in utilizing for the connection of at least one electrode in direct electrical communication with one of the contacts one conductor or a plurality of conductors of appropriate shape so as to partially or totally balance the electrodynamic forces which the various sections of said conductor or conductors exert on the arc.

As an example and for purposes of illustration,

a drawing is hereto annexed, wherein:

Fig. 1 is a diagrammatic vertical cross section of a circuit-breaker embodying the invention.

Fig. 2 is a diagrammatic perspective illustration of another embodiment of the invention.

Fig. 3 is a diagrammatic perspective illustration of a third embodiment.

The circuit-breaker shown in Fig. 1 is composed of the fixed contact 1 and the movable contact 2. Contact 1 is provided with the fixed sparking contact 1' and the movable contact 2 with the fixed electrode 2. Said movable contact which opens the circuit-breaker by a displacement in the direction of arrow 20 passes through a slit in electrode 2' and is displaced perpendicularly to the axis of said same electrode. The electrical connection between members 2 and 2 is obtained by means of sliding contact 21 and conductor 22 supporting electrode 2'. The contacts, sparking contact and electrodes are exposed to a compressed fluid blast introduced through pipe 3, said pipe being terminated by nozzle 4 in the axis of which is disposed electrode 2'. Nozzle 4 communicates with chimney 5 at the other extremity of which is provided the flame baflie 6. Approximately in the common axis of said nozzle and said chimney and near the outlet of said chimney is disposed an extremity electrode 7 connected by a conductor to contact I. Said conductor is composed on the one hand of the elbow or angular member 9 comprising a horizontal portion 10, and on the other hand by the descending member 8 carrying at its lower extremity the extremity electrode 7. Said horizontal portion 10 of angular member 9 is disposed radially in chimney 5 and is connected to contact 1 by conducting member 11 situated outside said chimney in the plane of angular member 9. Said angular member, or at least that part of same situated within said chimney,

is covered over with insulating material.

When, through the action of the blast, the are between contacts 1 and 2 is driven onto members 2' and 'I, said are remains approximately straight between said members and cannot be deformed by electrodynamic forces produced by members 11, 9, 2 and 2 which constitute a loop with said arc. Such a deviation of the arc towards the right hand might take place if, as indicated in Fig. 1 of my copending U. S. patent application, the extremity electrode '7 was connected to conducting member 11 by a straight and horizontally disposed bar. But, due to the elbow 9, the extended portion 8 of said elbow limits or prevents this deflection of the are because the arc is thus removed from the active field of horizontal conductor 10. As a result, the arc is only subjected to the action of conductor 8 whereby it has a tendency to remain in the axis thereof. Were this defiectionto take place, the arc displaced towards the right would form in open loop with the descending portion 8 and the eleotrodynamic force created by said loop would tend to oppose the deformation of the are and to straighten same.

The same eflect takes place in the lower half of the arc-where contact 2 and electrode 2 dis posed at right angles also oppose the displacement of thearc towards the right.

For a given intensity of current the straightening efiect exerted on the arc depends on the length of the conductors provided for that purpose. By giving sufiiciently large dimensions to these conductors a complete compensation of electrodynamic effects may be obtained. Instead of bending, the angular member 9 through 90, it may equally be bent through an acute angle with apex disposed on the right hand of the extinguishing blast axis, electrode 7 remaining disposed in the centre.

It is to be noted that certain dispositions adopted. in my copending U. S. patent application already tend to prevent a deflection of the arc. As a matter of fact, in accordance with said patent application, an elongated form has already been given to the extremity electrodes directly connected to the contacts, said elongation having its longitudinal axis parallel to the extinguishing blast. In this manner, the arc flowing from the extremity of these electrodes tends to dispose itself in the prolongation of their common longitudinal axis. However, in certain cases this effect may be insufficient to maintain the arc in a straight line. The'effect may be considerably reinforced, in accordance with the invention, by fixing these electrodes on the extremities of conductors, that portion of said conductors nearest the electrodes being disposed on a common axis parallel to the extinguishing blast.

Fig. 2 shows diagrammatic-ally a second embodiment of the object of the invention. The chimney is indicated by dotted lines, but the extinguishing device identical to that of Fig. 1 is not shown. The single bent conductor or angular member 9 of Fig. 1 is replaced in this embodiment by a series of three conductors symmetrically disposed about the axis of the extinguishing blast. Each said conductor comprises a radial rigid member 10 fixed to extremity electrode '7, said members being spaced at an angular distance of 120 apart. The outer extremities of members 10 are connected to contact 1 by conducting members 11 disposed on the outside of the chimney in a parallel direction to the distance 2-'7 and to the extinguishing blast. The distance between said conducting members 11 and the arc 2-7 should be at least equal to half the length of said are 2'7. The lower extremities of the conducting members farthest from contact 1 are'connected to said contact by conductors 12 circumposed around the chimney.

The effect of this disposition is analogous to that previously described. As each of the three angular conducting members 10, 11 has atendency to deflect the arc 2'7 beyond the centre of the chimney, the electrodynamic forces are compensated. Instead of three conductors 10, 11 a greater number of said conductors may be employed, or even two such conductors disposed in a radial plane on either side of the axis of the chimney maybe utilized.

Finally, Fig. 3 shows a third embodiment of the invention. In this diagrammatic embodiment a series of four bent conductors 10 supporting by their upper extremities electrode 7 are situated entirely in the interior of chimney 5. The cage thus formed by said bent conductors 10 is terminated at the base by conducting ring 13 disposed on nozzle 4. The compensation of the electrodynamic forces takes place in same manner as in Fi 2.

In all the embodiments described, electrodes connected to the movable contact through resistances may be disposed along the line 2'-7. The extinguishing fluid may be a gas or a liquid.

Having now particularly described and ascertained the nature of 'my said invention and in what manner the same is to be performed, I declare that what I claim is:

1. In an electric circuit breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishing fluid blast against said contacts, said blast being directed in transverse direction to the displacement of the movable contact, a fixed electrode connected by a conductor to one of said contacts, a fixed extremity electrode connected to the other contact through a second conductor, said extremity electrode being disposed behind said electrode considered in the direction of said blast in such manner that under the influence of said blast the arc will be transferred unto said two electrodes, and means for compensating at least partially the electrodynamic forces exerted by said conductors on said are disposed between said electrodes.

2. In an electric circuit breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishingv blast the arc will be transferred unto said two electrodes, and one at leastpf said conductors being given an appropriate shape such that the electrodynamic forces which said conductor exerts on said are between said electrodes will be 1 at least partially compensated.

3. In an electric circuit breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishing -fluid blast against said contacts, said blast being directed in transverse direction to the displacement of the movable contact, a fixed electrode connected by a conductor to one of said contacts, a fixed extremity electrode connected to the other contact through a second conductor, the extremity of at least one of said conductors near its electrode being parallel to said extinguishing blast, and the two said electrodes being disposed one behind the other considered in the direction of said blast.

4. In an electric circuit breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishing fluid blast against said contacts, said blast being directed in, transverse direction to the displacement of the movable contact, a fixed electrode connected by a conductor to one of said contacts, a fixed extremity electrode connected to the other contact through a second conductor, said second conductor comprising an angular member with horizontal element and a descending element situated in the axis of said extinguishing blast,

said extremity electrode being fixed to the lowerconnected to one of said contacts by means of a conductor comprising an angular member with horizontal element and a descending element situated in the axis of said extinguishing blast, said extremity electrode being fixed to the lower extremity of said descending element, and said horizontal element of said angular member being connected to one or said contacts by means of a conducting member approximately parallel to the 'straight line joining said electrodes, the distance between said conducting member and said straight line being at least equal to halt the dis tance between said electrodes.

6. In an electric circuit-breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishing fluid blast against said contacts, said blast being directed in transverse direction to the displacement of the movable contact, a fixed electrode and a fixed extremity electrode disposed behind said contacts and one behind the other in the axis of said extinguishing blast, said fixed electrode being connected to one of, said contacts and said fixed extremity electrode being connected to the other movable contacts between which an arc is developed, means ior projecting an extinguishing fluid blast against said contacts, said blast being directed in transverse direction to the displacement of the movable contact, a fixed electrode and a fixed extremity electrode disposed behind said contacts and one behind the other in the axis of said extinguishing blast, a chimney surrounding the two said electrodes, said fixed electrode being connected to one of said contacts and said fixed extremity electrode being connected to the other contact, this latter connection being realized by means of a series of conductors symmetrically disposed about the axis of said extinguishing blast, each element of said series of conductors comprising a portion parallel to said extinguishing blast and a radial portion, said radial portion traversing said chimney, the fraction of said radial portion situated inside said chimney being covered over with insulating material.

8. In an electric circuit-breaker, two relatively movable contacts between which an arc is developed, means for projecting an extinguishing fiuid blast against said contacts, said blast being directed in transverse direction to the displacement of the movable contact, a fixed electrode and a fixed extremity electrode disposed behind said contacts and one behind the other in the axis of said extinguishing blast, a chimney surrounding the two said electrodes, said fixed electrode being connected to one oi. said contacts and said fixed extremity electrode being connected to the other contact, this latter connection being realized by means of a series of curved conductors disposed in the'interior of said chimney symmetrically about the axis of said extinguishing blast, each element of said series of conductors comprising a radial portion and a portion parallel to said extinguishing blast.

ANDRE CLERC. 

